Enhanced-Type Quantitative Luminescence Recognition for Per- and Polyfluoroalkyl Substances (PFAS) by a Metal-Organic Framework Single Crystal.

Rapid and quantitative detection of per- and polyfluoroalkyl substances (PFAS) remains a critical challenge in environmental monitoring due to their low light absorption capacities. Luminescent sensing based on metal-organic frameworks (MOFs) enables analyte-specific optical responses through well-defined host-guest interactions, though conventional MOF powders as sensing materials face limitations in practical deployment for their stabilities and recyclable capacities. Herein, we report a millimeter-sized luminescent MOF single crystal that functions as a reusable sensor for PFAS, exhibiting an enhanced-type luminescence response upon analyte binding. In contrast to MOF powders, which often suffer from suspension instability and material loss during recycling, the single-crystal format offers robust structural integrity, direct handling, and facile recovery. The sensor exhibits exponential luminescence responses toward five commonly encountered PFAS and retains its sensing performance for 10 cycles. This work presents a durable and scalable luminescent platform for PFAS detection and underscores the role of dimensional control in advancing MOF-based sensing technologies.